Voltage to current converters are well known electronic building blocks for many circuit applications. As is well known to those having skill in the art, a voltage to current converter, also known as a transconductor, provides an output current that is directly proportional to an input voltage and which is independent of the load impedance. Voltage to current converters are widely used where it is necessary to generate a current signal in proportion to a given voltage signal.
For example, voltage to current converters are used in signal processors. The performance of signal processors is dependent on interface circuits such as voltage to current and current to voltage converters. In addition, analog four quadrant multipliers, using voltage to current converters, play important roles in the construction of convolvers, correlators, adaptive filters, and complex analog signal processors. Other computational circuits that use a voltage to current converter as part of their structure include multipliers, dividers, squaring circuits, integrators, and difference of squares circuits.
As technology advances, there exists a need for faster and more linear devices. As system speeds increase, voltage to current converter speed must also increase, so that the voltage to current converter does not produce a bottleneck in a system. Moreover, as system accuracy requirements increase, greater linearity demands are placed on the voltage to current converter. Finally, many systems are capable of processing both balanced and unbalanced inputs. Accordingly, there is a need for a voltage to current converter which is capable of receiving both balanced and unbalanced inputs.